1. Field
The following description relates to a 3D image display apparatus having a wide viewing angle by adjusting a direction in which light is emitted.
2. Description of Related Art
The 3D image display apparatus is considered by many to be the “next generation” flat panel display device. A three-dimensional (3D) image of a 3D image display apparatus is realized by implementing the principle of stereoscopic vision. The principle of stereoscopic vision provides that both eyes of a human being see an object at the same time.
Binocular parallax is a characteristic that occurs because of the left eye and right eye being positioned about 65 mm apart. Binocular parallax is the most important factor producing a 3D effect.
3D image displays are generally classified into displays that require the use of glasses to view 3D images and displays that do not require the use of glasses to view 3D images. Displays that do not require the use of glasses to view 3D images divide an image into an image for the left eye and an image for the right eye. Displays that do not require the use of glasses to view 3D images are classified into parallax barrier-type displays and lenticular-type displays.
The parallax barrier-type display alternately displays images that should be seen respectively by the left and right eyes in the form of a vertical pattern or a photo using an extremely thin vertical lattice column, i.e., a barrier. By doing so, a vertical pattern image that is to be provided to the left eye and a vertical pattern image that is to be provided to the right eye are separated by the barrier. Images are thereby seen by the left and the right eyes from different viewpoints, respectively, so that a stereo image is perceived.
The lenticular-type display arranges images corresponding to the left and right eyes on a focusing surface of a lenticular lens. When the left and right eyes observe the images through the lenticular lens, the arranged images are incident to the left and right eyes according to a directivity feature of the lens so that a stereo image is perceived.
However, in both the parallax barrier-type display and the lenticular-type display, a period, a focal length, and a direction of the barrier or the lens are fixed, thereby serving to limit ranges in which 3D images are seen. For example, the direction in which the 3D images are seen is set according to the arrangement direction of the lenticular lens or the barrier. Thus, the 3D images may be seen in only one of a transverse mode and a longitudinal mode. In addition, resolution is reduced according to the number of views in the parallax barrier-type display or the lenticular-type display.